Insulated wire connector



E. P. BANCROFT INSULATED WIRE CONNECTOR.

octw 3, 1944.

Filed Julyv 29 y1941 Patented Oct. 3, 1944 INSULATED wmE CONNECTOR Erwin P. Bancroft, Brooklyn, N. Y., assignor to International Standard Electric Corporation, yNew York, N. Y., a corporation of Delaware Appneationruly 29, 1941,-serm No. 404,505

18 Claims.

'I'his invention relates to connectorsv for insulated wires and more particularly that type of connector by means of which connections may be made without the necessity of removing the insulation from the wire.A

The particular object of the invention is to pro- Vvide a connector which is inexpensive, simple to use, and which will make a connection substantially as strong as the wire itself.

A further object of the invention is to Aprovide a4 connector` which is sultantially moistureproof.

Another object of the invention is to provide a connector into which the two wires to be connected may be inserted and then pulled taut, thereby providing a solid connection of extremely low resistance and permanence.

'Ihe present invention is designed particularly for army use. Conductors used by the signal corps for field service usually have a stranded core consisting of several steel wires and a number of copper wires. The steel wires are for the purpose of increasing the tensile strength of the conductors but their use makes ordinary splicing of conductors diicult on account of the1 stiff-v ness of the ste'el. The usual method of` splicing such conductors is to remove about six inches of insulation from the ends toA-be spliced and then the conductors arel knotted together by a square knot and taped up. This method of splicing is slow and diflicult especially when performed under dangerous conditions, and in any case results in a bulky uneven joint.

The present invention providesfa simplev connector for conductors by which circuits may be quickly connected, without removing insulation from the conductors, and which may be used eiilciently in darkness which is particularly important for some army operations.

Other objects of the invention will be apparent from the followingdescription, and from the appended claims:

Fig. l is a plan view showing a vsection of the preferred form of the connector and the operating mechanism therefor. n

Fig. 2 is a front View showing the arrangement of parts of the connector for connecting two pairs of wires. I

Fig. 3 is a modification of the mechanism of Fig. 1.

Fig. 4 is a second modification of the mechanism of Fig. 1. l

Fig. 5 is an end view of Fig. 1. Fig. 6 is a top view of a toothed cam.

Figs. 1 and 2 yshow a connector for connecting two pairs of wires. For the sake of clearness, the drawingis enlarged to about twice the size of the connector. In this embodiment of. the invention housing I of insulatingv material, preferably formed by a molding process, is shown to be composed of three sections, 2, 3, and 4 held' together by screws 5 or by any other suitable means. Channels 6 and I extending partway through the housing in opposite directions are` for theV purpose of receiving a pair of conductors which are to be connected to each other. In opposite sides of a recess I0 formed between each pair of channels are pivot holes to receive pivots I2 on each of which issupported a connector member I3 provided with points I4. Each connector member is provided near the ends thereof with pivots I5 which carry a clamping bar I1. Bushings I8 preferably of soft rubber are provided in each channel.

The respective channels have a slight bend or undulation at one or more places as indicated by reference character 2li.

The invention operates as follows: The ends of insulated wires 22 to be connected are inserted in the proper channels. The inner ends 2l of bushings I8' are slightlysmaller than the diameter of the insulated wire, so that when the wire is inserted therethrough the bushing will grip the insulation tightly Aancl prevent moisture entering the connector. 'The assembled structure of -connectors I3 and clamping barsl 'I constitutes a collapsible parallel motion device. When wires are inserted in to the connector through channels 6 and 'l the parallel motion device will collapse about the pivots I2 and open the channels through which the wire may pass. 'Each wire is pushed into the connector until it reaches the bottom of its channel and past al1 of the points I@ of the connector. The channels are so shaped, for example having a bend 20, that asthe wire passes the last connector point it is forced against the point. When tension is applied tothe wires,

the points I4 will dig into the insulation, piercing the latter and causing the parallel motion device just described to straighten yout again.

' This forces clamping bars I'I towards the opposite surface of the channel and clamps the Wire and insulation securely in the connector. The points I4 of the connectors I3 in piercing the insulation make rm contact with the wire. The greater the tension on the wire the greater the clamping effects of points I4 and bars I1 against the conductor and the tighter the wire is lheld -ing teeth 41 from the channel.

against the wall of the channel. 'I'he metal parts are made preferably from 'a non-corrosive metal, such for example, as stainless steel or Monel metal in order to insure permanent good contact with the wires.

The large ends ofgthe bushings I8 are made to iit snugly in recesses in housing I provided therefor, and when the wire is pushed through the bushing, the cavity within the housing and within the bushing 'becomes substantially moistureproof.

Another modification of the invention is shown in Fig. 3 wherein the collapsible framework described above is replaced by eccentric cams substantially fiat on'opposite sides and provided with teeth 3| at oppositely disposed arcs. 'I'he cams are pivoted at 32, and means such as pins 33 are provided to limit the extent of rotation of the cams in a clockwise direction as shown in the drawing. Undulations 34 are provided in the channel to insure engagement of the insulation of the conductors and teeth 3|'. When the wires are pushed into the channels of a connector of this kind, the cams rotate on the engagement of the insulation of the Wires with the cam teeth, and open up a channel through which the wire may pass, and when an attempt is made to withdraw the wires, the points on the metal cams pierce the insulation causing the cams to rotate in a counter-clockwise direction and clamp thewire securely between the opposite surface of the channel and the cam facings, the cam teeth having contacted `the conductors.

Another modication of the invention is shown in Fig. 4. In this case channels and 4I are provided in a housing 42. Between the channels,

Iin a suitable cavity in the housing,'are rollers 43. Wedge-shaped members 44, are movable horizontally over rollers 43 in guideways 45 formed in the housing as indicated by dotted lines in theV clamping surface on the edge thereof. The longer part of channels 40 and 4I slant at substantially the same angle as that of the slanting sides of the respective wedge-shaped members. Contact between the Wedge-shaped members is made by rollers 43 and also by ridges or beads 49 secured to, or formed on the Wedge-shaped members, which are in sliding contact with a ilat spring 50. lWhen the ends of a pair of insulated conductors are inserted in the respective channels, if lthe teeth of either member extend into the channel, they are engaged by the end of the conductor and the wedge-shaped member or members are forced back into their guideways 45 withdraw- The last tooth of each member, however, projects sufficiently far into the channel so as to engage the insulation of the conductor. When the `conductors are pulled outwardly the wedge-shaped pieces' are drawn toward the respective openings in the channels and the teeth thereon come out into the channel and penetrate the insulation and engage the conductors clamping them against the walls of the providing for shoulder clamping engagement with the wire insulation and proportioned to produce an effective holding pressure thereon. The angle of rest for the clamping members of the various embodiments is such that when tension is exerted on the wires the clamping members assume a Permanent clamping position from which they may not be restored by release of tension. Preferably the rest angle is such as not to .be released even by pushing on thewires. The spacing of the teeth on the various members is such that one or more twists will occur in the stranded conductor in the length of conductor engaged by the teeth which together with the clamping action of the device insures great resistance to tension.

The adjacent surfaces of housing sections-2, 3 and 4 may be coated with a suitable waterproofing preparation such as shellac or Bakelite varnish and fastened together before drying to further moisture-proof the connector.

The necks 2| of `the bushings may be coated with a suitable soft insulating compound of an ad- .'ing partly wrong side out so that some of the outer surface of the neck contacts the wire insulachannels with pressure increasing with the strain exerted on the wires.

In each of the above described embodiments of `the invention it will be noted that a. clamping sulation, thus, in addition to the contact teeth, 1|

tion. This presses the bushings tightly against the wire and improves the waterproof qualities of the connector.

What I claim is:

1. A connector for connecting a pair of insulated wires comprising a housing formed to provide channels to receive the wire ends in spaced and overlapping relation, rotatably supported connecting means interposed between the wires so positioned, said connecting means being provided with piercing points and clamping portions proportioned, responsive to a strain on the wires tending to withdraw them from the channels, to pierce the insulation for conductor contact and to clamp the wires against inwardly directed walls of the channels at points located substantially perpendicular to the longitudinal axis of the channels whereby the clamping portions assume a holding angle.

2. A connector for connecting a pair of insulated wires comprising a housing, channel `means in said housing to receive the ends of insulated wires to be `connected,l and a single connecting means provided with insulation piercing points and clamping portions, said connecting means'being adapted to pierce the insulationy of said Wires and contact the conductors thereof and to clamp the wires against walls of said channel means in response to a pull on either of 4said wires.

3. A connector f or connecting insulated wires comprising a housing of insulating material formed with a plurality of channels to receive the ends of insulated Wires in spaced and overlapping relation, toothed connecting means rotatably supported in position interposed between the wire ends to contact the conductors of the respective insulated wires in response to a pull onsaid wires and undulation means in at least one of said channels to insure the engagement of the insulation of the wire therein with at least one tooth of said toothed means. f

4. A connector for connecting insulated wires comprising a housing, a pair of channels extending into said housing in opposite directions, and connecting means common to both channels provided with piercing points and pivoted between said channels for penetrating the insulation on wires inserted into said channels and contacting the conductors thereof and means discomprising a housing, a plurality of channels in said housing to receive sections of the ends-of insulated wires to be connected, clamping means vprovided with piercing teeth in each channel, and

undulation means in at least one of said channels to insure the engagement of at least one of the teeth on said clamping means with the insulation of wire inserted into the channel to assure piercing of said insulation, and means for causing said clamping means to engage the wire in response to pressure from the insulation thereof on one of said teeth. y

6. A connector to permit connecting insulated wires without removing the insulation therefrom comprising a block of insulating material, channels extending part way through said block from each end thereof to receive the insulated ends of wires to be connected. an undulation formed in each channel, wire retaining means movable relative to said channels comprising a plurality of teeth for each channel, said retaining means being moved when the teeth thereof are engaged by a wire being-forced into said channel to partially withdraw said teeth from the channel permitting the conductor to pass, and. supporting means for said retaining means which in cooperating with said undulation in response to a strain tending to withdraw the Wire from said channel will cause said teeth to be forced outwardly into said channel penetrating the insulation and engaging said conductor and locking the conductor against further withdrawal.

7. A connector comprising a housing formed with a channel to receive the ends of a pair of conductors to be connected, conductor connectingV and retaining means in said channel and adapted to yield on the insertion of a conductor, means on said conducting and retaining means responsive to a strain on either conductor for penetrating the insulation of both conductors and other means on said connecting and retaining means for clamping the insulation as Well as the conductors against opposed walls of said channel.

8. A connector for insulated wires comprising a housing, a pair of channels extending part way through said housing, in opposite directions, a collapsible framework comprising a plurality of members provided with points at the ends thereof and pivoted at their midpoints on pivots disposed between the channels, clamping bars pivotally straighten up forcing the points through the insulation into the stranded conductors of the wire and at the same time the wiresare clamped by the clamping bar against the side of the channel.

9. Ajconnector according to claim 8 in which the points are effective to penetratev a length ci' Wire sufficient to include one twist of thestrands in a stranded conductor.

10. A connector according to claim 8 in which the clamping area is wider than the thickness of the points.

11. A connector according to claim 8in which the angle of rest of the collapsible framework is sufficiently great when in clamping position as, to prevent collapse of the framework due to a subsequent reverse pressure on the wires.

12. A connector for insulated wire comprisingl means for supporting said eccentric means dis' posed between said channels, and a plurality of teeth on said eccentric means arranged to partially withdraw from said channel when engaged by a wire being inserted into a channel permitting the wire to pass beyond said teeth, and to engage and penetrate the insulation on the wire and contact the conductor thereof when the wire is moved in the opposite direction and at the same time to clamp the wire securely against the wall of the channel.

13. A connector according to claim 12. wherein the eccentric means have shoulder means proportioned to effect added clamping pressure on the wire against the wall of the channel.

14. A connector according to claim 12 wherein the eccentric means comprise a pair of toothed Wheels disposed at least the distance of one twist of a stranded conductor from each other.

15. A connector according to claim l2 wherein the channels are provided with one or more undulations to insure the engagement of the insulation of a conductor with the teeth on the eccentric means.

16. A connector for insulated wires comprising a housing, a pair of channels extending part way through said housing, a guideway along each channel, a wedge-shaped member in each guideway provided with teeth projecting into the channel, said channel being so positioned in respect t0 said guideway that said teeth partially withdraw from said channel when engaged by the end of a pie'ce of wire being inserted into the channel, and emerge when the wire is moved in the opposite direction penetrating the insulation,

contacting Athe conductor, and clamping the wire against the wall of the channel.

17. A connector according to claim 16 in which the angle of the wedge-shaped members in respect to the position of the channel is such that when once set in clamping position, the wedge is immovable by a reverse pressure on the wire.

18. A connector according to claim 16 in which the edge of the wedge is wider than the tee thereon to provide a, clamping surface. 

